The present invention lies in the field of waste treatment. Waste such as municipal sewage or industrial effluent contains many inorganic, organic, and harmful microbiological materials, most of which are only partially degraded by conventional treatments. Chemical oxidation has been suggested for use to convert such materials to removable and harmless oxides but oxidation processes heretofore utilized have been inefficient and have only been capable of oxidizing a small portion of the contaminants normally found in domestic or industrial waste.
Thus, oxidants such as potassium permanganate (KMnO.sub.4) and chlorine (Cl.sub.2) have been used in many localities to disinfect or to improve the taste and odor qualities of municipal drinking water. These chemicals are not practical for waste treatment, however, because they lack sufficient oxidizing power to degrade many waste constituents and because they leave residual permanganate and chlorine, as the case may be, which must be removed before the treated water can be re-used or returned to the natural environment.
Ozone has also been used in the past to treat contaminated articles or water (U.S. Pat. Nos. 3,445,001, 3,549,528, 2,812,861). Unlike the materials just mentioned, ozone is an extremely powerful oxidant, yet it does not leave a harmful residue. As is well-known, the ozone molecule (0.sub.3) is unstable and decomposes to oxygen (0.sub.2) over a relatively short period of time. Thus, ozone does have the potential oxidizing power for waste treatment and its residue (oxygen) is beneficial rather than harmful. However, ozone has not heretofore been used for bulk waste treatment because means have not been available wherein ozone could be made to effectively react with the solid constituents of waste and, in any event, the cost of the necessary quantity of ozone required for bulk waste treatment has been prohibitive.
Another serious problem faced in the waste treatment art has been the inability to handle the solid constituents normally found in waste water. Waste effluent such as raw or secondary sewage normally contains a substantial quantity of solids which are difficult to handle physically and are difficult to oxidize.
Conventional mechanical means for breaking down solids in waste solutions often are unsatisfactory or fail entirely due to the large mass of the material being treated and/or the nature of these solids. A gummy or sticky residue can be the result of such mechanical treatment. For this reason, the art has, on occasion, suggested the use of sonic energy in the treatment of waste materials for purposes such as removing solids from filtering screens and/or precipitating solid particles (U.S. Pat. No. 3,489,679), breaking certain kinds of emulsions (U.S. Pat. No. 3,200,567), mixing, solubilizing, or causing the reaction of gases (U.S. Pat. Nos. 3,549,528, 2,717,874), or killing microorganisms (U.S. Pat. No. 3,366,654). Mechanical oscillations have also been suggested for stirring and/or promoting aeration or settling of waste materials (U.S. Pat. Nos. 3,264,213 and 2,770,593).
Additional background which may be of interest may be found in the following: U.S. Pat. Nos. 3,123,043; 1,195,067; 2,958,655; 2,771,416; 3,382,980; 2,138,349; 3,068,172; 2,864,502; 3,421,999; 2,417,722; 3,481,868; 2,874,316; 3,546,114; 3,320,161; 2,660,559; 3,153,530; 3,448,045.
Other References PA0 Treatment with ozone -- d. c. o'donovan -- Journal Americal Water Works Association, Vol. 57, No. 9, 1965. PA0 Disinfection of drinking water with ozone -- v. a. hann, Journal American Water Works Association, Vol. 48, No. 10, 1956. PA0 The advanced waste treatment research program -- 1962-1964, u.s. department of Health, Education and Welfare, AWTR-14, April, 1965. PA0 Development of a new type of rapid sand filter -- r. e. hebert, Journal of the Sanitary Engineering Division, proceedings of The American Society of Civil Engineers, Vol. 92, No. SA1, 1966. PA0 A new method of treatment for surface water supplies -- e. w. j. diaper -- presented at the Fall meeting of the New York Section, AWWA, 1969. PA0 Action of ozone on tastes and odors and coliform organisms -- marcus P. Powel et al. -- Journal of American Water Works Assoc., December 1952. PA0 The ozonation of turret and other scottish waters -- r. m. campbell and M. B. Pescod -- Journal of Institute of Water Engineers, 19:2:101-125, 1965. PA0 Use of ozone in the reclamation of water from sewage effluent -- p. l. boucher et al. -- paper presented at a meeting of The Institution of Public Health Engineers, London, December, 1967. PA0 Chemical Engineering, March, 1958 -- pp. 63, 64. PA0 Put ozone to work treating plant waste water -- plant Engineering -- November, 1966. PA0 Ozone counters waste cyanide's lethal punch -- chemical Engineering, Mar. 24, 1958. PA0 The ozonation of cyanide wastes -- richard G. Tyler, Purdue University, 1951. PA0 Ozone in air pollution abatement -- w. e. cromwell, I/EC Industrial Wastes, Workbook Feature, June, 1959. PA0 Ozonation at whiting: 26 years Later -- James F. Bartuska -- Public Works, August, 1967. PA0 Ozone in water treatment and waste water renovation -- d. thirumuthi -- W. & S. W. Reference Number -- 1968.